Curative resection after percutaneous drainage followed by preoperative panitumumab monotherapy for locally advanced sigmoid colon cancer with intra-abdominal abscess: a case report.

BACKGROUND: The gold standard treatment for locally advanced colon cancer is curative surgery followed by adjuvant chemotherapy, although this approach is associated with serious concerns, such as high recurrence rates and occasionally unnecessary oversurgery. Neoadjuvant chemotherapy may be a promising strategy for overcoming these issues. This study reports a case of a recurrence-free patient who underwent curative resection without significant organ dysfunction after preoperative chemotherapy for locally advanced sigmoid colon cancer. The tumor coexisted with a large intra-abdominal abscess, and the patient was quite frail at the first visit. We performed percutaneous drainage followed by preoperative panitumumab monotherapy, which yielded favorable outcomes. CASE PRESENTATION: A 78-year-old frail woman was emergently transferred to our hospital with fever and abdominal pain. The diagnosis was locally advanced sigmoid colon cancer stage IIIC (T4bN2aM0) with a large intra-abdominal abscess. Immediate curative surgery was inappropriate, considering both tumor progression and the patient's frailty. We performed percutaneous drainage and colostomy construction, which was followed by seven cycles of preoperative panitumumab monotherapy without significant adverse events. After these treatments, inflammation was well controlled, and the tumor shrank remarkably. Furthermore, the patient recovered well from frailty; therefore, curative sigmoidectomy combined with resection of the left ovary and stoma closure was possible without any postoperative complications. The final pathological finding was T3N0M0, stage IIA disease. The patient was recurrence-free and had no significant organ dysfunction 21 months after the curative surgery. CONCLUSIONS: The management of intra-abdominal abscesses and tailor-made preoperative chemotherapy based on the patient's frailty may have been the key factors responsible for the favorable course of this patient. Although further research is needed on the appropriateness of percutaneous drainage for malignancies related to intra-abdominal abscesses and preoperative panitumumab use for locally advanced colon cancer, the study findings can serve as reference for managing similar cases in an aging society.

[Laparoscopic Abdominoperineal Resection of the Rectum in a Case with Pagetoid Spread of Anal Canal Carcinoma].

The patient, a man in his 60s, first noticed an elevated lesion around the anus 3 years ago. The lesion failed to subside with the topical drug preparations prescribed at a local clinic, and the patient was referred to the Department of Dermatology of our hospital for further workup and treatment. The findings of biopsy from the lesion suggested skin infiltration of anal canal carcinoma, and the patient was referred to the Department of Surgery. Examination here revealed only induration of the anal canal, with no abnormality of the rectal mucosa even when the endoscope was reversed to visualize the rectum. Examination by various imaging modalities failed to reveal any metastases to the lymph nodes or distant organs, and the primary lesion remained unidentified. Laparoscopic abdominoperineal excision of the rectum was performed, beginning with anal manipulation. First, a 15-mm margin was set on the skin from the tumor edge, and the skin stump was divided into 4 equal portions. After confirming by rapid intraoperative frozen-section examination that the margin was negative along the full circumference, anal manipulation was performed, leaving a distance in the vertical direction immediately below the tumor. Upon completion of the anal manipulation, intraperitoneal manipulation was performed in a routine manner. The anal skin was relaxed subcutaneously, as done during mastectomy, and the subsequent suture closure could be done smoothly. The tumor was classified as pT1bN0M0, pStage Ⅰ. The experience with this case indicates that biopsy should be proactively employed for the diagnosis in such cases, and that proactive skin biopsy is useful when dealing with intractable anal skin lesions.

[Axillary Lymph Node Recurrence after Curative Surgery for Transverse Colon Cancer-A Case Report].

We report the rare case of an 89-year-old female with axillary lymph node recurrence after curative surgery for transverse colon cancer who had undergone right hemicolectomy with D3 lymphadenectomy with an uneventful postoperative course. Pathological examination confirmed the tumor's status as tub2>sig, T4aN3M0, and pStage Ⅲc, and signet-ring cell carcinoma was remarkably found in the metastatic lymph node. Genetic testing revealed wild-type RAS, a BRAF mutation, and a high MSI. After 9 months of follow-up without adjuvant chemotherapy, CEA increased sharply to 41.3 ng/mL by 9 months postoperatively, and CT showed nodules in the right axilla, adrenal gland, and retroperitoneum. PET-CT showed abnormal fluorodeoxyglucose uptake in the same regions. A core needle biopsy of the axillary lymph node revealed signet-ring cell carcinoma, which was diagnosed as a recurrence of transverse colon cancer. Although we suggested chemotherapy due to the unresectable recurrence of colorectal cancer, she preferred to receive supportive care instead. Three months after the recurrence was diagnosed, CEA increased to 248.4 ng/mL, and CT showed enlargement of the axillary lesion and a new lesion in the hilum of the lung.

[Brain Metastasis Following Conversion Surgery for Sigmoid Colon Cancer-A Case Report].

A 64-year-old man was diagnosed with KRAS-mutant type sigmoid colon cancer with metastasis in the lung, liver, left adrenal gland, and para-aortic lymph node(T3N1M1b, Stage ⅣB[Union for International Cancer Control 8th edition]). Laparoscopic transverse colostomy was performed to treat colonic obstruction. Subsequently, a combination regimen of capecitabine plus oxaliplatin plus bevacizumab was administered. After 5 courses of chemotherapy, the S8 liver tumor disappeared completely. Sigmoidectomy, para-aortic lymph node dissection, and left adrenal gland resection were performed. After 3 months, right S3 segmental pneumonectomy and right S8 and S10 partial pneumonectomy were performed. R0 resection for the primary lesion and metastatic lesions of the chest and abdomen was achieved. Following the conversion surgery, he was administered the adjuvant chemotherapy regimen of uracil-tegafur plus Leucovorin. After 2 courses of chemotherapy, he presented to our hospital complaining of vomiting and dizziness. Contrast-enhanced magnetic resonance imaging revealed multiple brain metastases. Thus, we should be mindful of the possibility of brain metastasis in cases of unresectable colon cancer showing satisfactory response to chemotherapy with an indication of conversion surgery.

[A Case of Recurrent Gastric GIST Who Survived for Long after Laparoscopic Resection and Imatinib Therapy].

A man patient in his 70s underwent left nephrectomy and laparoscopic partial gastrectomy for the treatment of a left renal cell carcinoma and gastrointestinal stromal tumor(GIST)arising from the stomach. Histopathologically, both the renal cell carcinoma and GIST were kit-positive, CD34-positive, and S-100 protein-negative, and the Ki-67 index was about 40% as determined by the hot spot method, so that it was diagnosed as an intermediate-group GIST. After surgery, the patient was followed without adjuvant therapy, as he did not wish to receive postoperative chemotherapy. A computed tomography(CT)conducted 3 years after the surgery revealed tumorous shadows in the abdominal wall, inferior periesophageal region, and dorsal aspect of the pancreas. Positron emission tomography(PET)-CT showed fluorodeoxyglucose(FDG) accumulation in these lesions. Therefore, based on a suspicion of recurrent renal cell carcinoma or GIST, we carried out abdominal wall tumor resection for both exploratory and diagnostic purposes, which yielded histopathological diagnosis of GIST, with features similar to those observed at the time of the initial operation. Because the number of tumors remained unchanged during the subsequent follow-up period, the tumorous lesions in the periesophageal region and on the dorsal aspect of the pancreas were resected laparoscopically. Each of the resected tumors showed histological features consistent with GIST. The patient was started on oral imatinib therapy after this operation. To date(5 years after the surgery for the recurrent tumors and 8 years after the initial operation), the patient has remained free of recurrence. The pattern of tumor recurrence noted in the present case(ie, metastasis/dissemination to the skeletal muscles)is relatively rare, and few reports have been published concerning long-term survivors through multidisciplinary treatment (surgical treatment and others). We report this case with a review of the literature.

[A Case of Unresectable Advanced Gastric Cancer Successfully Treated with Conversion Surgery].

A man in his 70s consulted a local clinic with a chief complaint of difficulty eating. Upper gastrointestinal endoscopy revealed a type 4 tumor spreading irregularly from immediately below the esophageal cardia to the lower gastric body. The patient was referred to our hospital with a diagnosis of advanced gastric cancer(human epidermal growth factor receptor 2 [HER2]-positive moderately-differentiated adenocarcinoma)accompanied by lymph node enlargement. We planned an open total gastrectomy after staging laparoscopy to rule out dissemination because peritoneal dissemination could not be ruled out using computed tomography(CT). To perform a total gastrectomy, a celiotomy was done after staging laparoscopy results suggested that dissemination was unlikely. However, the border between the pericardial lymph nodes and the pancreas or peritoneal artery was not visible, forcing us to terminate the staging laparotomy based on a judgment of unresectable locally advanced gastric cancer. Therefore, the patient was administered 6 cycles of combined S-1/CDDP plus trastuzumab as the primary therapy. The response to therapy was favorable, and we scheduled a surgical resection. However, the scheduled surgery was rescheduled because of COVID-19 pneumonia, and R0 resection was finally performed after the 7th cycle of S-1/CDDP plus trastuzumab therapy. Histopathologically, the regional lymph node metastasis had disappeared, the viable tumor remained within the mucosal layer, and scarring was evident from the submucosal layer to the serosa. In recent years, conversion surgery for unresectable gastric cancer has been sporadically reported. However, we are unable to definitively opine on whether this kind of surgery may contribute to improving the prognosis, resection remains indispensable for radical treatment. We report this case along with a review of the literature.

Splenic Abscess due to a Perforated Duodenal Ulcer Successfully Treated with Endoscopic Ultrasound-Guided Transgastric Drainage.

Splenic abscesses are rare, with a reported prevalence of 0.14-0.7% in autopsy studies. The treatment options for splenic abscesses include intravenous antimicrobial therapy, percutaneous drainage, and splenectomy. Although the dissemination of endoscopic ultrasound (EUS) intervention techniques has made it possible to perform puncture and drainage via the transgastrointestinal route for intra-abdominal abscesses where the percutaneous route has been difficult, there have been few reports of EUS-guided drainage of splenic abscesses. A case of a splenic abscess associated with a perforated duodenal ulcer that was successfully treated with EUS-guided transgastric drainage is described. An 89-year-old Asian woman with a perforated duodenal ulcer underwent surgery at another hospital. After surgery, the patient developed a splenic abscess, for which percutaneous treatment was anatomically difficult. Therefore, she was referred to our hospital for treatment of the splenic abscess using EUS-guided drainage. EUS-guided transgastric drainage was performed under sedation using a convex EUS scope. The splenic abscess, measuring approximately 4 × 3 cm2, was punctured using a 19-gauge aspiration needle. A 6-Fr pigtail nasocystic drainage tube was placed in the abscess cavity. The procedure was completed without any complications. After EUS-guided drainage, the abscess cavity decreased in size over time, and the patient had a good clinical course and was subsequently discharged. EUS-guided drainage of splenic abscesses may be a safe and effective therapeutic alternative to percutaneous drainage and surgery; however, large-scale investigations are required to confirm the present findings.

[Rectal Neuroendocrine Tumor G2 of Measuring Less Than 1 cm in Diameter with Lymph Node Metastases-A Case Report].

A 40-year-old man visited our hospital with rectal submucosal tumors measuring 5 mm and the 7 mm as detected by colonoscopy, following which an endoscopic submucosal resection was performed. Pathological examination revealed that the tumors was neuroendocrine tumor(NET); the tumor measuring 5 mm was NET G1 without lymphatic and venous invasion, while the 7 mm size was NET G2 with venous invasion but without lymphatic invasion. Lymph node and distant metastasis were not observed by computed tomography. Informed consent was obtained and he agreed to undergo additional rectal resection. Laparoscopic low anterior resection was performed and pathological examination enabled a diagnosis of rectal neuroendocrine tumor with regional lymph node metastases(T1a, N1, M0, Stage ⅢB[Union for International Cancer Control 8th edition]). Post-surgery, he was followed up for 3 years, without recurrence. This report suggests that the determination of treatment plan for rectal neuroendocrine tumor measuring less than 1 cm in diameter should be done carefully.

Quantitative evaluation of MSI testing using NGS detects the imperceptible microsatellite changed caused by MSH6 deficiency.

Microsatellite instability (MSI) is an effective biomarker for diagnosing Lynch syndrome (LS) and predicting the responsiveness of cancer therapy. MSI testing is conventionally performed by capillary electrophoresis, and MSI status is judged by visual assessment of allele size change. Here, we attempted to develop a quantitative evaluation model of MSI using next-generation sequencing (NGS). Microsatellite markers were analyzed in tumor and non-tumor tissues of colorectal cancer patients by NGS after a single multiplex polymerase chain reaction amplification. The read counts corresponding to microsatellite loci lengths were calculated independently of mapping against a reference genome, and their distribution was digitized by weighted mean. Weighted mean differences between tumor and non-tumor samples with different MSI status were assessed, and cut-off values for each marker in the discovery cohort were determined. Each microsatellite maker was defined as unstable if the weighted mean difference was greater than the cut-off value. In the discovery cohort, the evaluation model demonstrated sensitivity and specificity of 100% for all markers. In the validation cohort, MSI status determined by the new model was consistent with the outcome of the conventional method in 29/30 cases (97%). The single inconsistent case was classified as low-frequency MSI by the conventional method but considered MSI-high by NGS. Genetic testing for mismatch repair genes revealed a pathogenic variant in MSH6 in the discordant case. We successfully developed a quantitative evaluation method for determining MSI status using NGS. This is a robust and sensitive method and could improve LS diagnosis.

[R0 Resection following Chemotherapy for Colon Cancer Liver Metastasis Close to the Inferior Vena Cava and Hepatic Vein Confluence-A Case Report].

A 78-year-old man was diagnosed with sigmoid colon cancer, and laparoscopic sigmoidectomy was performed. On pathological examination, he was diagnosed with RAS-wild type sigmoid colon cancer with regional lymph node metastasis (T3, N1, M0, Stage ⅢB[Union for International Cancer Control 8th edition]). Computed tomography revealed S8 and S7 liver metastasis, 3 months after the initial surgery. The location of the S8 tumor was close to the inferior vena cava(IVC), right hepatic vein(RHV)and segment Ⅷ hepatic vein(V8). He was administered cetuximab plus modified FOLFOX6. After 6 courses of chemotherapy, the S8 and S7 liver tumor shrank. S8 plus 4 plus 1 and S7 partial hepatectomy was performed and R0 resection was achieved. The RHV and V8 were resected, while right superficial and middle hepatic veins were preserved. An IVC invasion was not observed. He was administered 12 courses of adjuvant modified FOLFOX6. After the partial hepatectomy, he has been followed up for 1.5 years with no recurrence.

[A Case of Adenocarcinoma Arising from an Ectopic Pancreas of the Stomach Presenting as Pyloric Stenosis].

The patient was a 37-year-old man who visited a neighborhood clinic complaining of nausea and upper abdominal pain. Since examination revealed abdominal distention, he was referred to our hospital. Abdominal computed tomography at our hospital revealed retention of gastric contents and contrast-enhancing wall thickening localized to the pyloric region. Upper gastrointestinal endoscopy showed stenosis involving the entire circumference of the pylorus. However, multiple biopsies failed to reveal any evidence of malignancy. Four dilatations were performed, with no improvement. Therefore, the patient was referred to the Department of Surgery. Since malignant disease could not be ruled out, laparoscopic distal gastrectomy with D2 lymph node dissection was performed. Histopathological examination of the resected specimen revealed the presence of ectopic pancreatic tissue in the proper muscle layer of the pylorus. Adenocarcinoma invading and proliferating into the surrounding ectopic mucosal lesion was observed. Therefore, the patient was diagnosed with adenocarcinoma arising from ectopic pancreas. The possibility of ectopic pancreatic cancer may need to be considered in patients with pyloric stenosis caused by a submucosal tumor-like lesion.

[Long-Term Disease Control with Capecitabine plus Bevacizumab Therapy for an Elderly Patient with Unresectable Colon Cancer-A Case Report].

An 83-year-old man visited our hospital with liver tumors detected by abdominal ultrasonography. On investigation, he was diagnosed with sigmoid colon cancer with metastasis in the supraclavicular lymph node, liver, and para-aortic lymph node(T3N1M1b, Stage ⅣB[Union for International Cancer Control 8th edition]). He was administered combination therapy with capecitabine and bevacizumab owing to the increased age and Eastern Cooperative Oncology Group performance status score of 1. After 8 courses of chemotherapy, the primary tumor and liver metastases shrank. As he developed Grade 2 hand-foot syndrome, the dose of capecitabine was decreased to 75%(1,500 mg/m2)from the 11th course and to 50% (1,000 mg/m2)from the 31st course. Until 2 years after initiation of the chemotherapy, the patient showed progression-free survival. Heparinoid-containing moisturizer and steroid ointment were administered for treatment of hand-foot syndrome. This report suggests that capecitabine plus bevacizumab therapy can maintain the quality of life and is safe with dose reduction and treatment of adverse reactions for elderly patients with colon cancer.

[A Case of Small Bowel Perforation Caused by Malignant Lymphoma after Methotrexate Therapy for Rheumatoid Arthritis].

A 73-year-old woman had a history of medication, including methotrexate for rheumatoid arthritis, for 5 years. She had chronic epigastralgia for 2 weeks and found to have multiple submucosal tumors on upper gastrointestinal endoscopy in another hospital. She had a strong abdominal pain thereafter and diagnosed as having gastrointestinal perforation on the basis of CT scans. Abdominal examination revealed disseminated peritonitis, and emergency laparoscopic surgery was performed on the day of admission. A 1 cm perforation of the ileum was identified, and a 5 cm mass of the mesentery near the perforation was also identified. Small bowel partial resection, including both lesions, was performed. From the intraoperative findings, methotrexate-associated lymphoproliferative disorders(MTX-LPD)was suspected, and methotrexate was discontinued after the surgery. At a later date, the pathological result from both the surgical specimen and upper gastrointestinal endoscopy was diffuse large B cell lymphoma(DLBCL). CT scan, PET-CT scan, and upper gastrointestinal endoscopy were performed 1-2 months after surgery, and no tumor was identified. Currently, 6 months after the surgery, the patient is still alive without any progression of the lymphoma.

[Trastuzumab Combination Chemotherapy Followed by R0 Resection for Locally Advanced Human Epidermal Growth Factor Receptor 2-Positive Gastric Cancer-A Case Report].

A man in the 60s visited our hospital with the complaints of epigastralgia and weight loss. Following an investigation, he was diagnosed with human epidermal growth factor receptor 2(HER2)-positive gastric cancer with invasion to the pancreas (T4b[pancreas], N2, M0, Stage ⅣA[Union for International Cancer Control 8th edition]). Preoperatively, he was administered a chemotherapeutic regimen of S-1 and cisplatin plus trastuzumab. After 2 courses of chemotherapy, computed tomography revealed invasion to the abdominal wall and pyloric stenosis; however, invasion to the pancreas was obscured, and the lymph node metastases had shrunk. He underwent laparoscopic gastro-jejunostomy. After 4 courses of chemotherapy, his condition was considered stable. A laparoscopic distal gastrectomy was performed together with resection of the abdominal wall invasion. The pathological stage was pT4b(abdominal wall), pN0, M0, Stage ⅢA, and R0 resection was achieved. The patient was administered 4 courses of adjuvant capecitabine plus oxaliplatin therapy and 4 courses of capecitabine monotherapy. He has been followed-up for 1.5 years since the curative resection and has not developed recurrences. This case suggests the usefulness of multimodal therapy for locally advanced gastric cancer.

[A Case of Extrahepatic Bile Duct Carcinoid Tumor Involving Diagnostic Difficulties].

A patient in his 60s had undergone laparoscopic anterior resection for the treatment of carcinoma of the rectum in February 2016. Histopathologic examination revealed the lesion as a pT2(MP)n(-)M0, fStage Ⅰrectal cancer. One year post-surgery, contrast-enhanced computed tomography(CT)revealed enhancement of parts of the intrapancreatic distal bile ducts. Magnetic resonance cholangiopancreatography(MRCP)showed filling defects at the same site. Magnetic resonance imaging( MRI)with an endorectal coil(ERC)was then performed to identify reproducible bile duct filling defects. Neither cytology nor biopsy yielded any findings that definitely indicated malignancy. Intraductal ultrasonography(IDUS)led to the suspicion of a nonepithelial tumor or an enlarged lymph node. Repeated biopsies via ERC were performed based on the absence of evidence of malignancy and revealed the presence of some atypical cells within the lesions. Although no definitive diagnosis could be made, the patient was scheduled for surgery in June 2017 after obtaining his consent. Upon taping of the common bile duct during surgery, a tumor was palpable on the dorsal aspect of the pancreas. The bile duct tumor was completely excised and submitted for intraoperative diagnosis; the pancreatic dorsal aspect appeared to be totally split. There was no evidence of atypia in the neoplasm, which was therefore considered to be benign; however, malignancy could not be completely ruled out because the patient had presented with elevated serum levels of carbohydrate antigen(CA)19-9 once before the operation. After intraoperative consultation with the patient's family members, who were reluctant to provide consent for pancreaticoduodenectomy, we completed the operation with resection of the bile duct tumor, followed by choledochojejunostomy. The tumor was found to be chromogranin A(+), cluster of differentiation(CD)56(+/-), CA19-9(+, solely ductal structure), carcinoembryonic antigen(CEA)(+, solely ductal structure), and intranuclear p53(-), with an MIB- 1 index of<2%. With regard to neuroendocrine markers, a region that could potentially have been a carcinoid tumor, based on the findings on hematoxylin and eosin(HE)staining, and a lumenized superficial region showed positivity in toto. Therefore, the lesion as a whole was diagnosed as a G1 carcinoid neuroendocrine tumor(NET). However, the superficial lumenized layer was positive for both CA19-9 and CEA; therefore, the tumor was thought to concurrently have epithelial characteristics. The lateral stumpwas negative, while the status of the ablated region remained unclear. After discussing the histopathologic examination results with the patient and his family members, the patient's follow-upwas decided to consist of periodic checkups without any further surgical intervention. The patient has since remained free of recurrence. Carcinoid tumor of the bile duct is extremely rare but should be considered in cases involving bile duct tumors that show enhancement on imaging prior to surgery and for which no definitive diagnosis can be established despite repeated biopsy explorations.

[Pathological Complete Response Following Chemotherapy for Sigmoid Colon Cancer with Para-Aortic Lymph Node Metastasis-A Case Report].

A man in his 50s visitedour hospital with complaints of frequent urination, painful micturition, macrohematuria, and weight loss. On examination, he was diagnosed with RAS-wild-type sigmoid colon cancer invading the urinary bladder, ureter, andexternal iliac artery, with para-aortic lymph node metastasis(T4b, NX, M1a, Stage ⅣA according to the Union for International Cancer Control 8th edition guidelines)andsigmoid -vesical fistula. Thus, sigmoidcolostomy was performed. Postoperatively, S-1 plus oxaliplatin was administered. After 3 courses of chemotherapy, the primary tumor and para-aortic lymph node metastases shrunk. Moreover, after 8 courses of chemotherapy, further shrinkage of the primary tumor and paraaortic lymph node metastases was confirmed; however, tumor markers in the blood increased. Therefore, the patient received 3 additional courses of S-1 plus oxaliplatin plus cetuximab, which resultedin complete response. Sigmoidectomy, partial cystectomy, ureterectomy, resection of the external iliac artery, andreconstruction using a prosthetic vascular graft were performed. Subsequent pathological examination revealed no viable cancer cells(pathological response), achieving R0 resection. The patient has been followedup for 2.5 years after the curative resection, with no recurrence.

[Three Long-Surviving Cases of Peritoneal Metastasis after Colorectal Cancer Resection].

We experienced 3 impressive colorectal cancer patients who developed peritoneal recurrences and underwent surgery several times and survived for more than 5 years. Case No. 1 was of a 44-year-old woman who underwent right hemicolectomy for her stage II A ascending colon cancer. She developed left ovarian metastasis, which was resected 3 years later. Five years later, she developed a pelvic peritoneal recurrence, which was resected successfully. Thirteen years later, she is doing well. Case No. 2 was of a 61-year-old man who underwent transverse colectomy for his stage II B colon cancer. He developed ileus 2 years 9 months later due to peritoneal recurrence, which was removed successfully. He underwent another resection for peritoneal metastasis 2 years 6 months later. He was administered 15 courses of FOLFOX6. He has remained cancer-free since 2009. Case No. 3 was of a 62-year-old man who underwent sigmoidectomy for his stage II A colon cancer. One year 8 months later, he underwent resection for a painful abdominal wall metastasis. Eight months later, he developed another abdominal wall recurrence, which was resected successfully. He underwent thoracoscopic resection 4 times for lung metastases and was given 16 courses of FOLFOX6. In 2009, he developed pelvic peritoneal nodules, which were resected. He later needed lymphadenectomy twice. He has remained cancer-free for the last 5 years and 6 months. Curative resection must be performed for a patient with peritoneal recurrence of colorectal cancer when surgery is indicated.

[A Case of Complete Response to Computed Tomography-Guided Celiac Plexus Neurolysis of Pain Associated with Postoperative Recurrence of Colon Cancer].

The patient was a man in his 40s, who had undergone laparoscopic ileocecal resection with lymph node dissection(D3)for cecal cancer in January 2012. Histopathological examination of the resected specimens had revealed StageⅡ primary tumor with subserosal invasion and positive metastasis in 1-3 regional lymph nodes(pT2[SS]n1[+]). The pathological stage was Ⅲa(fStage Ⅲa), and the tumor showed RAS gene mutation. The patient was administered 5 cycles of postoperative adjuvant chemotherapy with oral tegafur/uracil(UFT)in combination with calcium folinate(UZEL). Abdominal computed tomography( CT)performed 1.5 years postoperatively revealed liver metastasis, and a laparoscopic partial hepatectomy was performed in August 2015. In addition, a node in the greater omentum, located in the inferior surface of the liver, was also resected. Histopathological examination of the resected specimens revealed peritoneal metastasis, based on the identification of the same type of adenocarcinoma as the colon cancer. The patient was given 8 cycles of adjuvant chemotherapy with capecitabine and oxaliplatin(CapeOX). Then, he presented with colonic ileus, caused by recurrent dissemination, and underwent a laparoscopic transverse colectomy in October 2015. Multiple perineal disseminations were found intraoperatively, and chemotherapy was initiated with irinotecan plus tegafur/gimeracil/oteracil(S-1)plus bevacizumab(IRIS/BV)for the recurrent and unresectable disease. After 27 cycles of this regimen, lung metastasis was detected; in addition, progression of the para-aortic node metastasis around the celiac plexus was also observed, and the patient was considered as having pro- gressive disease(PD). Treatment with trifluridine/tipiracil(TAS102)was started in September 2017. Prior to the initiation of this regimen, the dose of opioid rescue medication previously started for back and abdominal pain was rapidly increased. Accordingly, the base dose was increased, but the pain could not be controlled, and the major pain was consistently located along the area of innervation in the celiac plexus. Therefore, celiac plexus neurolysis(CPN)was performed as a local therapy. A CT-guided injection technique was used to administer urografin, bupivacaine, and absolute ethanol to complete the procedure. The patient was discharged without major complications, and the base opioid dose was gradually reduced. Since the patient did not require any rescue medication during daytime on some days, the reduction of the base opioid dose was significantly effective in improving the patient's quality of life(QOL). In patients with pain possibly caused by metastasis to the para-aortic nodes, this local therapy technique may be considered.

[A Case of Phrenic Nerve Paralysis During Adjuvant Chemotherapy for Rectal Cancer].

A man aged 66 years presented with pneumaturia as a major complaint. Cancer of the sigmoid colon with infiltration to the urinary bladder was diagnosed and the patient underwent colectomy of the sigmoid colon and partial cystectomy of the bladder in May 2015. Histopathologic examinations revealed pT4b, Si(bladder), pN(-), cM0, fStage II . Because intestinal sub-obstruction and lymphatic invasion were present, CapeOX was administered as an adjunctive chemotherapy for the high-risk Stage II cancer. Because Grade 2 peripheral neuropathy appeared as a side effect, the dose was decreased to 80% from the 3 cycle. After the 7 cycle, cough and disturbed breathing appeared. The chest CT scans did not reveal drug-induced interstitial pneumonia, but indicated an elevated right diaphragm and zosteroid changes in the medial lobe of the right lung due to discoid atelectatic condition. The Grade 1 respiratory symptoms were mild, and the lung field was considered to exhibit no problems. Thus, the 8 cycle was administered. The symptoms disappeared after about 2 weeks following completion of oral administration of capecitabine. The diaphragm also recovered to its original height. In the attached document, the frequency is unknown and "dyspnea" is written for L-OHP and capecitabine, respectively. It is unknown whether phrenic nerve paralysis occurs. However, because other organic lesions were absent and the symptoms appeared during chemotherapy, the possibility is not deniable. At present, 2 years postoperatively, recurrent lesions in the mediastinum and recurrent respiratory difficulties are absent. Generally, although phrenic nerve paralysis is not considered to be a specific side effect, it was considered that for respiratory difficulties, CT reveals not only the affected condition in the lung fields, but is also useful for detection.

Metastatic Pattern of Stage IV Colorectal Cancer with High-Frequency Microsatellite Instability as a Prognostic Factor.

BACKGROUND: A recent clinical trial on the immune check-point inhibitor pembrolizumab demonstrated that microsatellite instability (MSI) is a good biomarker for response to this inhibitor. However, clinicopathological features of advanced colorectal cancer (CRC) with high-frequency MSI (MSI-H) are unclear. PATIENTS AND METHODS: A total of 2,439 surgically resected CRC tissues were analyzed for MSI status, and mutational status of V-Ki-Ras2 Kirsten rat sarcoma 2 viral oncogene homolog (KRAS), neuroblastoma RAS viral oncogene homolog (NRAS) and v-Raf murine sarcoma viral oncogene homolog B (BRAF). Stage IV cases were selected, and clinical and molecular features were evaluated. RESULTS: There was no significant survival difference observed between MSI-H CRC and microsatellite-stable (MSS) CRC in patients with stage IV disease (3.92 vs. 2.50 years; p=0.766). However, hematogenous and lymphogenous metastasis-dominant CRC with MSI-H demonstrated poor prognosis, whereas peritoneal metastasis-dominant CRC with MSI-H demonstrated good prognosis, (1.33 vs. 5.2 years; p=0.006). CONCLUSION: Prognosis of stage IV CRC with MSI-H depended on the metastatic pattern. These findings provide useful information for the adaptation of CRC immunotherapy.